1. Field of the Invention
The invention relates to an aircraft comprising a fuselage and at least two substantially hollow cylindrical lifting bodies which are applied to the fuselage and comprise a plurality of rotor blades extending over the periphery of the lifting body, with the periphery of the lifting body being partially covered by at least one tail surface.
Such an aircraft is especially provided with a system of special lifting bodies which are configured as rotors, having a rotary axis which is arranged substantially parallel to the longitudinal axis of the aircraft. Each rotor is provided with a certain number of airfoil-like rotor blades which are substantially arranged on two disk-like end bodies in such a way that during a full rotation of the lifting body (rotor) the central axis of the rotor blade performs a circular movement spaced from the rotary axis as the radius, and that the rotor blade can be changed individually in its position during a full rotation. A defined action of force (e.g. lifting force, lateral force) can be produced on the aircraft in every momentary position of the rotor blade.
Numerous efforts have been undertaken to combine the advantages of an aircraft with those of a helicopter. Of special interest is the property of helicopters to be able to start and land vertically or to hover in the air whenever necessary in order to rescue people or in order to fulfill special transport and mounting flight maneuvers or similar tasks. The disadvantageous aspect in current helicopters is the high technical complexity, especially in the field of rotor control and the high risk of crashes even in the case of slight contact of the rotating rotor blades with obstructions such as the tips of trees or rock walls. Especially conditions during assignments in Alpine rescue operations are exceptionally critical because on the one hand a position as close as possible to a rock wall would be required, and on the other hand the slightest collision could lead to fatal consequences. Work can therefore only proceed by observing respectively large safety margins. A further disadvantage is the high fuel consumption of helicopters, even in cruising flight.
In order to avoid such disadvantages, so-called VTOL or STOL aircraft have been developed which with respect to their configuration are principally similar to airplanes, but are equipped with the ability, through various technical measures, to be able to start and land vertically, or can at least make do with extremely short take-off and landing runways.
Such a solution has been disclosed in EP 0 918 686 A (corresponding to U.S. Pat. No. 6,231,004) for example. This specification describes an airplane comprising airfoils which are substantially formed by cross-flow rotors. It is thus possible to produce a vertically downwardly directed air stream through a respective deflection of the air stream in order to enable a vertical take-off of the aircraft. The thrust can be deflected accordingly for cruising.
The disadvantageous aspect in this known solution is on the one hand that the airfoils which are optimized for generating lift have a high air resistance, so that fuel consumption is excessively high, especially at higher flight speeds, and that the aircraft in total has a relatively large wing span. It therefore requires much space and cannot be used or only with difficulty under conditions with limited available space.
Further aircraft have been described in U.S. Pat. No. 4,519,562 A. The solution is complex and has a low efficiency, so that such a system was never accepted on the market. The rotors described in U.S. Pat. No. 6,261,051 B are also not suitable for representing an aircraft with vertical take-off capabilities that can be used in practice.
A further aircraft which generates lift by using modified cross-flow fans is disclosed in DE 196 34 522 A. Apart from the question of the proper function of such an aircraft which is not obviously clear, it also comes with the disadvantages as explained above.
A further aircraft with a cross-flow rotor as a drive element is also known from U.S. Pat. No. 6,016,992 A. A very large cross-sectional surface in the direction of flight is also obtained in this case as a result of the cross-flow rotor, and the need for space is as high as in the solutions described above.
A further known aircraft with the possibility of vertical take-off is disclosed in U.S. Pat. No. 3,361,386 A. Extremely variable airfoils are provided in this aircraft which are provided with openings for gas outlet. Fuel consumption is extremely high as a result of the system-inherent adverse efficiency of such a system.
Close to the state of the art is also the drive concept for watercraft which is known as Voith-Schneider drive. This drive system which has already been known for approximately 75 years differs substantially in such a way that the swiveling movement of the individual blades during a full rotation of the live ring occurs at a fixed kinematic ratio with respect to each other. Thrust is thus always only possible in one direction. In contrast to this, a second force component in the transversal direction can be produced by the inventive rotating lifting body, irrespective of a first force component, e.g. an evenly remaining vertical lifting component.
The present invention relates to further embodiments of VTOL aircraft which are equipped with rotating lifting bodies whose rotary axis is arranged substantially parallel to the longitudinal axis of the aircraft.